An electronic device such as a digital camera or a smart phone can acquire an image by using an image sensor that converts light into electric signals through a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). Normally, the image sensor detects infrared (IR) light as well as visible light, thus deteriorating the color reproduction rate of an image. Accordingly, the electronic device has an IR cut filter (also referred to as an IR cut-off filter or an IRCF) so as to obtain a clearer image by blocking light in the IR band.
A typical IR cut filter may include a film plate formed to absorb IR light of a specific band and further include reflective coating films coated on both sides of the film plate to reflect IR light. In this IR cut filter, when a light containing a large amount of IR rays enters, a part of IR light is not absorbed into the film plate and repeatedly reflected by the reflective coating films on both sides of the film plate. Unfortunately, such multiple reflections of IR light occurring in the IR cut filter often causes a light-blurring phenomenon in an image obtained from the image sensor.